JPH0443526Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a precast concrete member.

[Conventional technology]

Precast concrete members are, for example, formed into structures such as columns and beams, or finishing materials such as exterior wall materials in buildings, etc., and can improve productivity and shorten construction time by prefabricating component parts. It is often used as something that can be measured. In particular, long precast concrete members with reinforcing members such as prefabricated reinforcing bars buried in the concrete can be used as formwork members when constructing floors and walls, simplifying structural construction. It is attracting attention as

Conventionally, as this type of long precast concrete member, one in which a concrete portion in which a reinforcing member is buried is formed into a flat plate shape is known. The representative version is called the Omnia version.

[Problem that the invention attempts to solve]

However, in the case of the above-described conventional structure, since the concrete portion is flat, the yield strength as a long precast concrete member exerted in cooperation with the reinforcing member was not so large. Therefore, for example, when this long precast concrete member is used as a member that also serves as a floor form, it is difficult to increase the distance that can be constructed without shoring.

In view of the above-mentioned circumstances, an object of the present invention is to provide a long precast concrete member with higher yield strength.

[Means for solving problems]

The characteristic structure of the long precast concrete member according to the present invention is that one chord member of a reinforcing member is formed by connecting upper and lower chord members along the longitudinal direction to a concrete part having a gutter-like cross-sectional shape in the longitudinal direction. The reinforcing member and the concrete portion are buried so that the entirety thereof has a substantially symmetrical shape when viewed in longitudinal cross section.

[Effect]

In other words, the concrete part in which one of the chord members of the reinforcing member is buried is curved like a gutter in a longitudinal cross-sectional view, forming a shell structure and being able to resist larger external forces. Together, a long precast concrete member with greater strength than before can be obtained.

[Effect of idea]

As a result, for example, when this long precast concrete member is used as a member for floor formwork, it can be erected over a longer span without shoring, further simplifying the construction work. In addition, it has become possible to more effectively utilize the advantages of long precast concrete members that are combined with this type of reinforcing member.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows a cross section of a long precast concrete member 1 according to the present invention.

This long precast concrete member 1 is
Its cross-sectional shape is semi-cylindrical. A plurality of tension steel members 2 for introducing prestress are embedded in the concrete portion 1a along the longitudinal direction.

A tensile force is applied to each tension steel member 2 when the long precast concrete member 1 is formed, and when the concrete hardens, the tensile force is released, and a compressive force is applied to the long precast concrete member 1. It's getting old. Therefore, it is capable of resisting tensile forces that are larger than normal.

The tension steel members 2 are arranged one each at both ends of the open side of the concrete portion 1a, and five tension steel members 2 are arranged at the center. When this long precast concrete member 1 is formed, as shown in FIG. 20mm～
30mm). At the location where the long precast concrete member 1 is used, this swelling is offset by applying a load or the like from the open side.

Moreover, reinforcing bars 3 arranged to connect the tension steel members 2 are buried inside the concrete portion 1a, and these reinforcing bars 3 bear shear stress.

Furthermore, as shown in Figures 1 to 3, 1
A reinforcing member 4 is provided which includes an upper chord member 4A, one lower chord member 4B, and a plurality of connecting members 4C that connect the upper and lower chord members 4A and 4B.

One upper chord member 4A and one lower chord member 4B are:
All of them are deformed steel bars, that is, reinforcing bars. Further, the plurality of connecting members 4C are flat steel, that is, steel frame materials,
By its both ends, the upper and lower chord members 4A, 4
By winding and pinching B, they are connected and fixed. As shown in FIG. 4, the reinforcing member 4 has a ladder-like shape when viewed from the side.

This reinforcing member 4 has its upper chord member 4A located in the groove space 1b surrounded by the concrete portion 1a, and its lower chord member 4B located in the concrete portion 1a.
It is buried in As shown in FIG. 1, the reinforcing member 4 and the concrete portion 1a as a whole are substantially symmetrical in longitudinal cross-sectional view.

This reinforcing member 4 resists bending and shearing due to the load acting on the long precast concrete member 1, thereby increasing the proof strength of the long precast concrete member 1. Therefore, when this long precast concrete member 1 is used as a member that also serves as a formwork for constructing a floor slab to be described later, it can be constructed over a long distance without shoring.

In addition, when this long precast concrete member 1 is used as a semi-prefabricated member that also serves as a formwork, the reinforcing member 4 is embedded in the concrete cast in the groove space 1b. , acts as a shear connector that helps integrate the long precast concrete member 1 with concrete cast on site.

In the floor slab described later, this reinforcing member 4 and the concrete portion 1 in which it is buried.
Since the function of the beam is achieved by a, the thickness of the floor slab can be reduced.

Further, when the elongated precast concrete member 1 is suspended and moved by a crane or the like, a hanging hook can be hung on the reinforcing member 4 to hang it.

Note that the cross-sectional shape of the concrete portion 1a in the longitudinal direction can be changed in various ways instead of the semi-cylindrical shape described in the previous embodiment. A few examples are listed below.

<1> As shown in Figure 5A, the cylinder is divided into three parts. Although not shown, the number of divisions may be four or more.

<2> As shown in Figure 5B, an ellipse is divided into two along the short axis. Although not shown, the shape may be an ellipse divided into two along the long axis.

<3> As shown in Figure 5C, the concrete portion 1a shall have a flange attached to each of the open side edges. In the illustrated embodiment, the edges of the flanges are actually processed so that the long precast concrete members 1 can be constructed side by side.

<4> Although not shown, various cross-sectional shapes such as a parabolic cross-section, a cycloid cross-section, and a catenary cross-section can be formed.

Further, the configuration of the reinforcing member 4 can also be changed as appropriate. Next, some examples will be explained.

<5> The one shown in Figure 6 A is a modified version of the one shown in Figure 4, with upper and lower string members 4A and 4B.
A connecting member 4C that connects and fixes the strings is inclined with respect to each of the upper and lower chord members 4A and 4B to form a lattice member. In this embodiment, the entire reinforcing member 4 forms a truss when viewed from the side. Note that the upper and lower chord members 4A and 4B are both reinforcing bars, and the connecting member 4C is a steel frame member. Further, the upper and lower chord members 4A, 4B are rolled and held by the connecting member 4C in the same manner as in the previous embodiment.

<6> In the case shown in Figure 6B, the upper chord material 4A is
In this arrangement, two lower chord members 4B are provided, and the two lower chord members 4B and upper chord member 4A are connected by a connecting member 4C that is approximately orthogonal to each of the upper and lower chord members 4A and 4B. It is fixed. Connecting members 4C connecting the upper chord member 4A and one lower chord member 4B, and connecting members 4C connecting the upper chord member 4A and the other lower chord member 4B are alternately arranged. In addition, the upper and lower string materials 4A and 4B
Both are reinforced steel materials, and the connecting member 4C is a steel frame material.

<7> The one shown in Fig. 6C is a modification of the one shown in Fig. 6B, and includes a connecting member 4C that connects the upper chord member 4A and one lower chord member 4B, and a connecting member 4C that connects the upper chord member 4A and the other lower chord member. A connecting member 4C that connects the lower chord member 4B is integrally formed by bending a single flat steel. In addition, the upper and lower string members 4A,
4B is a reinforcing material, and the connecting member 4C is a steel frame material.

<8> The one shown in Figure 6 D is a modification of the one shown in Figure 6 B, in which the connecting member 4C is inclined with respect to the upper and lower chord members 4A and 4B, respectively, to form a lattice member. It is. In addition, the upper and lower string members 4
Both A and 4B are reinforcing bars, and the connecting member 4C is a steel frame material.

<9> What is shown in FIG. 6 E is the structure of the reinforcing member 4 shown in FIG. 6 A, in which the upper and lower chord members 4A,
Angle steel, which is a steel frame material, is used as 4B. Further, the connecting member 4C is a steel frame material, and the connecting member 4C and the upper and lower chord members 4A, 4B are connected and fixed by welding. In addition, Figure 4 or 6
A similar configuration can be adopted for the reinforcing member 4 shown in Figures B to D.

<10> What is shown in FIG. 6F is the configuration of the reinforcing member 4 shown in FIG. In addition, the connecting material 4C is a reinforcing bar material, and the connecting material 4C
The upper and lower chord members 4A and 4B are connected and fixed by welding. Incidentally, the reinforcing member 4 shown in FIG. 4 or FIG. 6 B to D can also have a similar configuration.

<11> The one shown in Fig. 6G is a structure in which one upper chord reinforcing bar 1a and two lower chord reinforcing bars 1b are connected and fixed by welding a connecting member 4C made of reinforcing bar material, and is a so-called omniar reinforcing bar. It is called.

Next, an example of the use of the long precast concrete member 1 according to the present invention is shown in Figs. 1 to 3, in which the long precast concrete member 1 having a semi-cylindrical cross-sectional shape in the longitudinal direction is used also as a floor formwork. An example will be explained in which the material is used as a semi-prepared member.

FIGS. 7A to 7D are schematic diagrams showing the steps of constructing a floor slab S in a building with a steel-framed reinforced concrete structure.

To explain the process in order, first, in the same manner as in the conventional method, column reinforcements 6 are arranged around the steel column 5, and a column formwork 7 is raised surrounding the column reinforcements 6 (see Fig. 7A).
Next, over the tops of the adjacent column forms 7,
Beam forms 9 and 10 are erected to cover the steel beam 8 from below (see Fig. 7B).

Thereafter, a floor form F is formed in the area surrounded by the four beam forms 9 and 10 (see FIG. 7C).
The floor formwork F includes a plurality of long precast concrete members 1 constructed across beam formworks 9 constructed in the girder direction, and a weir laid between adjacent long precast concrete members 1. Board 1
It consists of 1.

The long precast concrete member 1 is constructed with its open side facing upward. Also,
The dam plate 11 is specifically a keystone plate. As shown in FIG. 8, this weir plate 11 is placed in a notch 1c formed on the outer edge of the long precast concrete member 1.

Also, to explain the connection between the long precast concrete member 1 and the beam formwork 9 installed in the girder direction, as shown in FIG. A welded steel plate 13 is embedded and fixed, and the round steel 12 protruding from both ends of the long precast concrete member 1 and the steel beam 8 are welded and fixed. The side plates 9a of the beam formwork 9 installed in the girder direction are the long precast concrete members 1.
It is cut out to match the shape of the outer periphery.

After forming the floor formwork F as described above, reinforcing bars for the beams and floors are arranged, and this floor formwork F and the beam formwork 9,
Concrete is placed inside the column formwork 10 and the column formwork 7. In the floor formwork F, concrete enters the groove space 1b formed in the long precast concrete member 1, and buries the reinforcing member 4 located in this groove space 1b.

As a result, the ready-made concrete portion 1a constituting the long precast concrete member 1,
Together with the concrete C cast on site, the floor slab S is constructed (see Fig. 7D).

That is, long precast concrete members 1 with high strength obtained by forming the concrete portion 1a into a gutter shape are erected across the beam forms 9 at appropriate intervals, and these long precast concrete members By laying a keystone plate as the weir plate 11 between the two, it is possible to simplify or even eliminate the use of end pieces or pipe supports as shoring.

Therefore, after pouring concrete for the floor slab S, it is possible to start the next process on the floor directly below at an early stage, and with the reduction in formwork materials used, material costs and labor costs can be reduced. You will be able to do this.

In addition, when the elongated precast concrete members 1 having the cross-sectional shape shown in FIG.

In the previous embodiment, the long precast concrete member 1 was explained in which prestress was introduced in advance, but the long precast concrete member 1 according to the present invention does not necessarily have prestress introduced. You don't have to.

Note that although reference numerals are written in the claims section of the utility model registration for convenience of comparison with the drawings, the present invention is not limited to the structure of the attached drawings by such entry.

[Brief explanation of the drawing]

The drawings show an embodiment of a long precast concrete member according to the present invention, and FIG. 1 is a cross-sectional view of the long precast concrete member, FIG. 2 is a side view of the long precast concrete member, and FIG. 3 is a side view of the long precast concrete member. is a plan view of a long precast concrete member,
FIG. 4 is a perspective view of the reinforcing member, FIGS. 5A to 5C are schematic cross-sectional views corresponding to FIG. 1 showing other embodiments of the long precast concrete member, and FIGS. 7A to 7D are schematic perspective views showing the construction process of the floor slab, and FIG. 8 is a cross-sectional view of the floor formwork. FIG. 9 is a sectional view taken along the - line in FIG. 8. 1a... Concrete part, 4... Reinforcement member,
4A...Top chord material, 4B...Bottom chord material, 4C...Connection material.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. A concrete part 1a having a gutter-like cross-sectional shape in the longitudinal direction, upper and lower chord members 4A along the longitudinal direction,
One chord material 4 of the reinforcing member 4 formed by connecting 4B
B, the reinforcing member 4 and the concrete portion 1a
A long precast concrete member buried so that the entire part has a substantially symmetrical shape when viewed in longitudinal cross section. 2. The elongated precast concrete member according to claim 1, wherein the concrete portion 1a has a semi-cylindrical cross-sectional shape in the longitudinal direction. 3. Utility model registration claim 1 or 2, in which the reinforcing member 4 forms a truss frame.
A long precast concrete member according to any one of the items. 4. The elongated precast concrete member according to any one of claims 1 to 3, wherein the reinforcing member 4 is made of a steel frame material. 5. Any one of claims 1 to 3, wherein the reinforcing member 4 is made of a reinforcing bar material.
Long precast concrete members described in . 6. The elongated precast concrete member according to any one of claims 1 to 3, wherein the reinforcing member 4 is made of a combination of steel frames and reinforcing bars.